Ko Mae Ko

Ko Mae Ko is one of the limestone islands of the Ang Thong archipelago west of Ko Samui. Its main attraction is Thale Nai, the inland-looking saltwater lagoon surrounded by limestone walls. The island belongs administratively to Ang Thong Subdistrict in Ko Samui District. Thale Nai connects with the surrounding sea through passages in the limestone. The elevated viewing area reveals the contrast between the enclosed lagoon and the open Gulf. This is a landscape-viewing stop rather than an inhabited island destination; the lagoon and its surrounding slopes are the reason most visitors come. Visit on an authorised national park boat itinerary, usually from Ko Samui. Confirm the landing arrangements, walking access and time ashore with your operator; reaching the lagoon viewpoint involves climbing. Park admission is separate from boat pricing unless expressly included. The 2026 DNP seasonal closure declaration covers Ang Thong visitor sites from 1 November to 15 December; confirm any later notices and sea conditions before booking.